A woman who found out her partner was an undercover police officer paid to spy on her has said she was the victim of a conspiracy to rape.

Some officers from the Metropolitan Police entered into long-term sexual relationships with women after going undercover in order to infiltrate protest groups.

The actions of officers working for the Special Demonstration Squad (SDS), an undercover unit within Special Branch that existed until 2008, and for the National Public Order Intelligence Unit (NPOIU), which was operational until 2011, will be examined at the so-called spycops inquiry.

The Undercover Policing Inquiry (UCPI), which was launched in 2015, has already cost more than £10 million, and is not expected to deliver its final report until 2023.

The inquiry is investigating undercover operations conducted by police forces in England and Wales since 1968, involving hundreds of thousands of documents and the evidence of hundreds of witnesses.

A woman who found out her partner was a police spy told BBC Wales Investigates: “If you put all these things together, you have a team of officers conspiring to rape.”

She added: “They know there was no informed consent.

“It’s the whole gang of them, and there’s no other way of terming it for me than a gang.

“You’ve got mentors, you’ve got handlers, a whole backroom team of people monitoring – and directing, it would seem – their relationships, their activities.”

Scotland Yard said: “The historical work, deployment and actions of officers within the now-disbanded Special Demonstration Squad and the National Public Order Intelligence Unit will be fully explored and scrutinised by the Undercover Policing Inquiry (UCPI).

“The Metropolitan Police Service is providing every assistance so the inquiry can fully address the key issues it has identified, and can fulfil its terms of reference.

“The MPS has made clear its position on long-term, sexual relationships some undercover officers are known to have entered into with women in the past. Those relationships were wrong and should not have happened.

“Undercover policing is a lawful and important tactic that takes dangerous offenders off the streets and helps protect communities, but cases such as these demonstrate that some officers abused their positions.”

BBC Wales Investigates Undercover Cops: Abuse Of Duty will be broadcast on Monday at 8.30pm on BBC One Wales.